S329 Effect of Hormone Replacement Therapy on Outcomes of Hospitalized Postmenopausal Colorectal Cancer Patients: A Nationwide Analysis

Introduction: Previous studies have shown that postmenopausal hormone replacement therapy (HRT) which is commonly prescribed to postmenopausal women has been associated with reduced prevalence of colorectal cancer (CRC). Moreover small studies have also found that HRT could improve prognosis of CRC in postmenopausal women however data is very limited. Hence, we sought to analyze the association of HRT with CRC outcomes from the largest U.S. population-based cohort. Methods: National Inpatient Sample (NIS) and Healthcare Cost and Utilization Project (HCUP) data from the year 2020 was queried to identify postmenopausal women hospitalizations with concurrent diagnosis of HRT and CRC. Other diagnoses of interests and comorbidities were identified by previously validated International Classification of Diseases, Tenth RevisionClinical Modification (ICD-10-CM) codes. Outcomes of interest were all-cause in-hospital mortality and discharge to facilities. We performed weighted analysis using multivariable survey logistic regression to estimate the impact of HRT on outcomes of hospitalized patients with CRC. Results: We identified a total of 521,675 hospitalizations among postmenopausal CRC patients. Out of which 430,025 (82.4%) had long term use of HRT. Median age was 70 vs 73 (P < 0.01) and Whites were 80.8% vs 72% (P < 0.01) among the HRT group vs non-HRT. In unadjusted analysis, HRT was associated with lower in-hospital mortality (2.2% vs 4.4%; P < 0.01) but higher discharge to facility (24.2% vs 17.1%; P < 0.01). After adjusting for demographics, hospital-level characteristics, risk of mortality and confounding factors, HRT was independently associated with lower in-hospital mortality (adjusted odds ratio [aOR] 0.5; 95% confidence interval [CI] 0.5-0.6; P < 0.01) but higher discharge to facility (aOR 1.6; 95% CI 1.4-1.6, P < 0.01). Conclusion: Our study concludes that long term use of postmenopausal HRT is associated with lower all-cause mortality among hospitalized CRC patients. Our findings are consistent with prior studies. Given limitations of large data, further studies are required to establish causality and in-depth analysis.